kagis

https://www.reddit.com/r/askscience/comments/thj9zj/could_a_human_survive_on_a_planet_with_a_thinner/

So, the answer is yes. The term “partial pressure” is often heard in this topic: as long as at least 0.2 bar of pressure are produced by oxygen alone, then you can add as much (or as little) as you want of a diluent gas on top of it. Of course this diluent gas has to be inert enough to avoid interfering with respiration, e.g. helium or nitrogen.

I don’t think that that’s authoritative as a lower limit – the guy is just saying that what matters is the partial pressure of oxygen. Assuming that that is right…

There is an upper limit on the partial pressure of oxygen. Above 1.6 bars oxygen toxicity becomes a problem.

Yup an a scuba diver, 1.6 at rest is the most we use while decompressing. 1.4 is the recommendation while exercising and 1.2 if you’re doing a long dive.

The military, as I understand it can push up to 2.0, but they have people that are super fit & they test people for oxygen tolerance too.

These aren’t gonna be hard limits, though, just maximums on what you’d subject a person to intentionally.

https://www.checkyourmath.com/convert/pressure/atmospheres_bars.php

There are 1.01325 bars in an atmosphere.

https://en.wikipedia.org/wiki/Death_zone

The concentration of oxygen (O2) in air is 20.9% so the partial pressure of O2 (PO2) at sea level is about 21.2 kPa (6.3 inHg; 3.07 psi).

Humans have survived for 2 years at 5,950 m (19,520 ft) [475 millibars (14.0 inHg; 6.89 psi) of atmospheric pressure], which appears to be near the limit of the permanently tolerable highest altitude.[13]

So “normal” at sea level is 1 atmosphere, with 20.9% of that being oxygen.

If WP is correct, we can get down to 46% of that partial pressure of oxygen at normal atmospheric mix at sea level (though we couldn’t be climbing mountains then, would cut into our survivable altitude range). So we could get down to 9.614% atmospheric oxygen and be okay at sea level.

https://en.wikipedia.org/wiki/Oxygen_toxicity

Lambertsen concluded in 1987 that 0.5 bar (50 kPa) could be tolerated indefinitely.

So that’d be 50.7% oxygen, or about 2.42 times the partial pressure of oxygen at sea level.

Going off that range – 9.614% to 50.7% oxygen at sea level – we could handle all of the oxygen levels on the chart. But two important caveats:

• That’s only at sea level. The “dead zone” altitude on mountains and such would drop when the oxygen level is lower than it is in the current atmosphere.

• We probably wouldn’t perform as well as we do today towards the extremes. It might be survivable, but “survivable” can be a long way from “biologically optimal”.

According to this:

https://english.stackexchange.com/questions/27810/why-do-americans-call-single-beds-twin-beds

In the 1950s, a single was as wide as the average person’s shoulders. A twin was a single & a half. A double was two singles. A queen was a single & a twin. A king was 2 twins (or 3 singles). Nowadays, the single is forgotten, so everyone is confused. When I was a child in the 1950’s, my bed was a twin and you could put two first graders in it side by side. My best friend had a single bed, so when I slept over at her house, I slept in her bed and she slept on the floor.

EDIT: I don’t think that that’s correct, though, because while beds have become larger, it sounds like the twin was very much around in the 1950s.

https://www.ebohemians.com/a-guide-to-antique-bed-sizes-understanding-the-history-and-variations/

Single beds, also known as twin beds, are the smallest antique bed size and the most common size for children’s bedrooms. They were widely used in the late 19th and early 20th centuries and measured around 39 inches wide and 75 inches long. However, some antique single beds may be shorter, measuring around 72 inches long.

reads a few articles

Summary: On a number of their base models for some years, they didn’t include an engine immobilizer. The result is that one can break a window, use a screwdriver to quickly break open the steering column, yank out the ignition column, stick a USB charger plug in, turn, and the vehicle starts. In the Columbus and Milwaukee area, the “Kia Boys”, a group of kids and young teens – male, black, 12-14 – popularized stealing Kias on TikTok, with the “Kia Challenge”, where one steals a Kia and posts it to TikTok. They steal tens of thousands. The young age means that penalties are light. The vehicles generally aren’t stolen for parts or use, but to joyride in, often wind up wrecked. People in area generally buy steering wheel locks. Kia and Hyundai agree to start putting immobilizers in again.

I think it’d be more interesting to adjust for the number of units sold.

Otherwise, a lot of that is just going to be due to correlation with the number of units sold.

The most-endangered thing on there, the vaquita, appears to live in the Gulf of Mexico. The dot on the map for that is really too high – it’s a good way up California’s coast.